I am helping with a valve job on a 1930 KJ. The guides are worn out and some of the valves need to be replaced. I am having new valves made but I am not sure that the valves are original. The engine has run fine for years but the valve train needs some attention. The valves that were taken out seem to be very heavy, which could have an adverse effect on the valve train, such as excessive wear on the end of the valve and the dishing of the tappet adjusting bolt,(just my opinion). I have several questions regarding the material I should use for the valve guides, and the clearance between the valve and the guide. Also any information on helping the lubrication of the exhaust valves.